Lnk adaptor: novel negative regulator of B cell lymphopoiesis.

Originally thought to have the functions now ascribed to the linker for activation of T cells protein (LAT), Lnk is coming into its own as an adaptor protein that mediates signaling through several receptor pathways. An essential role for Lnk in B cell development and maturation was recently uncovered by Perlmutter and colleagues. Rudd discusses the role of Lnk in B cells and hypothesizes a mechanism whereby Lnk, and its closely related protein family members, the adaptor molecules containing pleckstrin homology (PH) and Src-homology 2 (SH2) domains (APS), and Src-homology 2-B protein (SH2-B), may mediate signal promotion or attenuation.